Connector with integrated heat sink

ABSTRACT

A receptacle connector defines a port. The port is provided with spring fingers that are configured to engage a mating module. The spring fingers are thermally coupled to a heat transfer plate that can be configured to provide part of a cage that defines the port. Fins can be mounted on or integrated into the heat transfer plate. In operation, thermal energy from an inserted module is transferred from the module to spring fingers and then to the heat transfer plate and then to a thermal dissipation system.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/785,065, filed Oct. 16, 2017, now U.S. Pat. No. 9,960,525, which is acontinuation of U.S. application Ser. No. 13/672,142, filed Nov. 8,2012, now U.S. Pat. No. 9,793,648, which claims priority to U.S.Provisional Application No. 61/556,890, filed Nov. 8, 2011 and to U.S.Provisional Application No. 61/640,786, filed May 1, 2012, all of whichare incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to field of electrical connectors, morespecifically to the field of input/output (I/O) connectors.

Description of Related Art

Typical I/O connector systems include a cable assembly and a boardmounted connector. The cable assembly, which commonly includes a pair ofplug connectors on opposite ends of a cable, is configured to transmitsignals over a desired distance. The board mounted connector, which istypically a receptacle positioned in a panel with the receptacleconfigured to receive and mate with the plug connector.

As data rates have increased, one issue that has been difficult toovercome is the physical limitation of medium that is used to transmitsignals from between the plug connectors. Passive cables, for example,are cost effective for shorter distances but tend to be limited withrespect to distance as signal frequencies increase. Active copper andfiber optic cables are well suited to transmit signals over longerdistances but require power and thus tend to create thermal issues ifthe connector system is not properly designed. One solution has been touse a riding heat sink on the receptacle but the existing solutions,while somewhat effective, have trouble providing sufficient thermalhandling capacity. Thus, certain individuals would appreciate furtherimprovements in thermal management.

BRIEF SUMMARY OF THE INVENTION

A receptacle connector includes a port configured to receive a matingmodule. The port is provided with spring fingers that are configured toengage the mating module. The spring fingers are in thermalcommunication with a heat transfer plate that is configured to providepart of the wall that defines the port. Fins can be mounted on the heattransfer plate. In operation, thermal energy from a module istransferred from the module to spring fingers and the thermal energy isin turn transferred from the spring fingers to the heat transfer plateand then to fins (if included). The connector system can be configuredso that air flows from front to rear and thus the depicted connectorsystem is suitable for use in an architecture such as a rack system thattypically direct air from one side of the rack (e.g., the front or back)to the other side of the rack. If desired, the receptacle can be astacked connector configuration with two vertically aligned ports.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 illustrates a perspective view of an embodiment of a connectorassembly.

FIG. 2 illustrates an exploded perspective view of the connectorassembly depicted in FIG. 1.

FIG. 3 illustrates a perspective view of an embodiment of a stackedreceptacle connector.

FIG. 4 illustrates a partially exploded perspective view of the stackedreceptacle connector depicted in FIG. 3.

FIG. 5 illustrates another partially exploded perspective view of thestacked receptacle connector depicted in FIG. 3.

FIG. 6 illustrates a perspective cross-sectional view of an embodimentof a partial receptacle connector system taken along line 6-6 in FIG. 1.

FIG. 7 illustrates a partial elevated side view of a cross-section of anembodiment of a port in a receptacle connector.

FIG. 8 illustrates a perspective cross-sectional view of a partialreceptacle connector system taken along line 8-8 in FIG. 1.

FIG. 9 illustrates a perspective exploded view of an embodiment of athermal management system.

FIG. 10 illustrates a flow chart of thermal transfer from a module.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description that follows describes exemplary embodimentsand is not intended to be limited to the expressly disclosedcombination(s). Therefore, unless otherwise noted, features disclosedherein may be combined together to form additional combinations thatwere not otherwise shown for purposes of brevity.

As can be appreciated from the figures, a receptacle connector 10 istypically mounted behind a bezel 20 (of which a partial bezel 20 isdepicted). If the bezel is considered positioned at a front of thereceptacle and the opposite end is considered a rear, then a systemarchitecture may allow for air flow from front to rear. If the systemarchitecture is set up to allow for air flow from front to rear then thebezel 20 can include air intake 25, which can be formed from one or moredesirably shaped apertures in the bezel. As can be appreciated, the sizeof the apertures, as well as the pattern of such apertures, is primarilydictated by the desired air flow needed to cool the system and thus aperson of skill in the art will be able to determined the desired airintake 25 configuration based on system requirements.

A connector system 1 includes a connector 10 that is positioned on acircuit board 5 and includes ports 30 position in openings 22 in thebezel 25 and the ports 30 are configured to receive mating plugconnectors. As depicted, the design allows for air to be pulled throughthe bezel 20. An EMI seal 26 and a gasket 28 help the connector 10 sealto the bezel 20.

As depicted, a shield assembly 50 includes a top cover 51 that joins afirst and second receptacle assembly 90 together. As depicted, theoptional top cover 51 includes an aperture 40 that can be used to directair flow away from a circuit board 5 while still joining two adjacentreceptacle connectors together. As the top cover 51 extends between twocage assemblies 100, the top cover also tends to create a rear passage42 that can be configured to direct air from the front toward the rear.

As depicted, each receptacle assembly 90 includes the cage assembly 100that comprises a main portion 100 b and a rear portion 100 a and furtherincludes heat transfer plates 125, 125′ that are mounted to wall 105 ofthe main portion. Positioned between the heat transfer plates 125, 125′is a center guide 110 that includes a surface 111 that can support theheat transfer plate 125. As can be appreciated, the surface can bestepped to allow sufficient space for the heat transfer plates 125. Ofcourse, it should be noted that the depicted receptacle 90 providesstacked ports 30. A lower profile version of a receptacle connector witha single port would also be suitable and could omit the optional centerguide 110 and instead have a single heat transfer plate 125. It shouldalso be noted that while the depicted system includes spring fingerplates 151, 152 on what can be considered a top and bottom side of theport 30, other configurations are contemplated. For configurations withlower thermal issues, for example, a single spring finger plate could beused. The spring finger plate and heat transfer plate could also beconfigured to engage one or two sides of a module (rather than the topand bottom of a module) with a thermal transfer area positioned above orbelow the module (rather than on the side as illustrated).

Each cage assembly 100 encloses a housing 200 that includes a mainportion 210 that supports nose portions 215, 215′. The nose portions215, 215′ each support a slot 220, 200′, respectively, that isconfigured to receive a paddle card from the mating module. A front cagewall 230 includes tails 232 that help define an electrical wall aroundthe main portion 210. As depicted, light pipes 245 may be positioned andconfigured to extend between and forward of the nose portions 215, 215′.

If desired the heat transfer plate can extend vertically beyond a singleport. For example, the heat transfer plate 125 depicted in FIG. 9 couldbe configured so that a main wall C extends vertically the height of twoports and side walls A, B each engage a single side of a plug insertedinto the corresponding port (side wall B engaging the top side and sidewall A engaging the bottom side). It should also be noted that ifdesired, the heat transfer plate need not be one piece but instead couldbe formed of multiple pieces. As can be appreciated, this allows for aheat transfer plate with a main wall that extends vertically along twostacked ports while still providing for side walls that engage twosurfaces of an inserted plug connector. As can be further appreciated,the main wall C will be along a first side 30 a of a port (or ports) andside wall A will be along a side 30 b of a port and side wall B will bealong a side 30 c of a port. It should be noted that the sides 30 b, 30c can be opposing sides of the same port of two different sides of twodifferent ports. It should further be noted that while the depicted heattransfer plate is depicted as having a U-shaped design, one side couldbe removed so as to provide a shape more like an L. It is also possibleto place the spring fingers directly on the main wall but such aconfiguration will tend to reduce the amount of thermal energy that canbe removed.

In addition, if a more complex heat transfer plate is desired, then theheat transfer plate have the main wall formed of a vapor chamber or someother system that has a lower thermal resistance than a copper plate.For most applications, however, a heat transfer plate formed of a copperplate will be sufficient. It should also be noted that fins 300 need notbe positioned on the side between connectors (as shown). Such a systemprovides certain benefits but if the system is designed to benefit fromairflow above the connector then it may be more desirable to have theheat transfer plate direct thermal energy up over the connector and toposition fins 300 (or other desirable thermal energy transfer systemssuch as is possible with liquid cooling and the like) above theconnector 10.

As can be appreciated, the depicted configuration beneficially has theability to allow for a stacked configuration and also takes advantage ofthe increased surface area that rectangular shaped module (such as anSFP style module) has on the top and bottom surface so as to minimizethermal resistance. In addition, providing spring finger plates onopposing sides helps provide a mechanically balanced system as theopposing spring fingers tend to center the module. It should be notedthat the contact force provided by each spring finger 161 can varydepending on the desired thermal resistance (increasing the contactforce will tend to improve thermal conductivity) and the desired moduleinsertion force (increasing the contact force will tend to increase therequired insertion force). Consequentially, the profile and contactforce, which could be, but is not limited to, in a range of about 100 to400 grams of force per spring finger, can be adjusted so as need to meetthe system requirements.

As depicted, the heat transfer plate 125 includes channels 130. Thedepicted channels 130 extend through the heat transfer plate 125 andprovide displacement regions for tails 163, 163′ of spring FIGS. 161,161′ when contacts 162′ 162′ of the spring fingers 161 engage aninserted module. Therefore, when a mating module is inserted in a firstdirection 166, the spring fingers 161 are translated in a seconddirection 164 and a third direction 165 and the second direction 154 andthe third direction 165 are opposite of each other. As can beappreciated, in alternative embodiments the function provided by thechannels could also be provided by depressions or slots in the transferplate 125 that did not extend through the heat transfer plate. Thus, thedisplacement region in the heat transfer plate 125 may be a depressionor channel that does not extend through the heat transfer plate.

The spring finger plates 151, 152, 153, 154 each include a plurality ofspring fingers 161, which each include contact surface 162, 162′ and atail 163, 163′. As depicted, the spring fingers 161 are arranged in rows160 and each row includes a plurality of spring fingers 161. It shouldbe noted that the depicted pattern of rows makes it straight forward toalign the channels 130 in the heat transfer plate 125 with tails 163,163′ so that when a module is inserted into the port 30, the tails 163,163′ can be displaced into the channels 130. The use of rows is notrequired, however, and other patterns could also be provided as desired.

The spring fingers 161 are configured to engage an inserted module so asto provide a number of thermal contacts to the inserted module. Thebenefit of such a design as compared to existing designs that tended touse a single plate to engage a module is that the spring fingers 161 canseparately engage the surface of the module and thus are better suitedto account for variations in surface flatness of the module. While thetotal surface area (as compared to a large plate typically used with ariding heat sink design) is reduced, it has been determined that the useof multiple springs is actually quite effective and in practice cansomewhat surprisingly provide lower thermal resistance between themodule and the spring finger plate than is typically provided between amodule and a floating heat sink with a planar surface.

The thermal resistance can be managed by increasing the spring forceassociated with each finger and by varying the number of spring fingers.Generally speaking, the limit on the spring force and the number ofspring fingers will be based on the maximum acceptable insertion forceand thermal energy that needs to be removed from the module that is tobe inserted.

The spring finger plates can be mounted on the heat transfer plates soas to minimize thermal resistance between the two structures. In anembodiment, for example, the spring finger plates can be soldered to theheat transfer plates with a reflow process. In an embodiment, the reflowprocess could take place in conjunction with the mounting of fins 300 tothe heat transfer plate so as to provide an efficient manufacturingprocess. Of course, other mounting methods could also be used (such asthe use of a thermal adhesive or the like). While a solder attach methodcan provide very low thermal resistance, thermally conductive adhesives(when kept thin) are also suitable because the total surface area issufficient to provide low thermal resistance between two matingstructures. It should be noted that in an embodiment the heat transferplate and the spring finger plate could be combined into a singlestructure, however such a structure would be more challenging tomanufacture in a high-volume process and therefore the two piececonstruction is believed to offer lower total costs.

The fins 300 are configured to provide an increased surface area so asto improve heat transfer from the receptacle to the air flowing over thereceptacle. As depicted, the fins 300 are configured to provide goodheat transfer for air flowing from front to rear (or vice versa). Theshape of the fins 300 can be varied, however, so as to be suitable forthe desired air flow direction and thus the depicted shape is merelyexemplary. It should be noted that the fins are optional and instead ofproviding fins, the surface of the heat transfer plate could be used. Inaddition, a system configured for liquid cooling could provide a conduitthat rests on the heat transfer plate and is configured to conduct heataway from the heat transfer plate. In addition, if fins were desired thefins could be formed as part of the heat transfer plate. As can beappreciated, however, one advantage of forming the fins separately fromthe heat transfer plate is that the fins can be designed for aparticular air flow configuration and positioned in a desiredorientation (e.g., on the side of the connector, above the connector,etc.), thus providing considerable flexibility in the design of theconnector.

As can be appreciated from FIG. 8, the fins 300 may take up considerablespace between two stacked connectors. Therefore, the size and theposition may be varied as discussed herein to allow for a reduction inthe spacing between ports 30.

In general, therefore, thermal energy from the module is transferred tothe spring fingers (and thus to the spring plate). If the spring plateis soldered to the heat transfer plate, the thermal resistance betweenthe spring finger plate and the heat transfer plate can be minimal.Similarly, if the optional fins are soldered to the heat transfer plate,thermal resistance can be minimized. Thus, referring to the thermalenergy path illustrated in FIG. 10, it is possible to have a temperaturedifference between a module and the fins to be less than 15 C and incertain embodiments to be about 10 C. In general, the largesttemperature drop (other than temperature drop between the fins and anyexternal air flowing over the fins) will be between the module and thespring finger plate and in an embodiment the temperature differencebetween the module and the spring finger can be substantially greaterthan the temperature difference between other components.

While various embodiments are contemplated, it should be noted that thedepicted configuration of the thermal pathway between the module and thefins is such that the channels can be aligned with the intended thermalpathway and thus have only a minimal impact on the thermal resistance.

As can be appreciated from FIG. 10, when a module is inserted into theconnector the thermal energy is generated by the module in step 400.This thermal energy is directed away from the module with spring fingersin step 410. Thermal energy is then transferred to the heat transferplate in step 420. Finally thermal energy is transferred to a systemthat directs thermal energy away from the system in step 430 (step 430,for example but without limitation, can be performed by the fins 300).It should be noted, however, that in certain systems the fins (or anyspecial thermal transfer system) can be omitted as the improved abilityto channel thermal energy away from the module may be sufficient to coolthe system. In many applications, however, the increased power output ofthe module may result in making some sort of thermal transfer systemdesirable.

Another embodiment of a receptacle connector that includes variations onthe features discussed above could be provided. The receptacle connectorcould include a cage assembly that is configured to enclose a housing.The cage assembly (which can be formed by a number of separate elementscombined together) includes a side aperture and a top aperture thatallows a thermal system to be used. The thermal system includes a heattransfer plate with a main wall and an upper side wall and a lower sidewall. Naturally, some other number of side walls could be added ifdesired and if desired, just one side wall might be used (although sucha system would tend to be most beneficial for a non-stackedconfiguration).

As can be appreciated, the main wall extends vertically along both portsand thus avoids the need for a thermal transition between the two ports(thus helping to keep thermal resistance low). If desired, and asdepicted, the main wall can even extend above top port so as to provideadditional surface area

As can be appreciated, while the two piece fin and wall design discussedabove with respect to FIGS. 1-9 is suitable, the main wall of thethermal transfer plate can be formed via an extrusion so that optionalfins are integral with the main wall, thus reducing potential thermaltransitions between two elements. The fins act as a thermal dissipationelement. Naturally, a liquid cooled solution with a liquid-filled vesselcould also be used as a thermal dissipation element to help transferthermal energy away from the main wall or one of the side walls (thusreplacing the fins). It is expected that the use of a liquid-cooledsolution would make integration of the heat transfer plate and thethermal dissipation element slightly more complicated (for example, thethermal dissipation element might benefit from being soldered to theheat transfer plate).

The upper side wall can include fins that extend away from the upperside wall in a first direction while the main wall includes fins thatextend away from the heat transfer plate in a second direction, thefirst direction and the section direction being perpendicular. Oneadvantage of this configuration is that an extruded fin design ispossible while allow for fins that are well suited to being positionedboth on the side and top of the corresponding connector.

The depicted upper side wall can support a spring finger plate thatincludes a finger that is configured to engage a wall of the cageassembly. The spring finger plate can also support a plurality of springfingers that can function similarly to the spring fingers discussedabove. Notably, the spring fingers extend away from the supporting sidewall and are configured to be deflected toward the supporting side wall.One difference is that the spring fingers don't need to include tailsthat require a recess in the supporting side wall. As can beappreciated, the inclusion or absence of tails will depend on thedesired contact interface and the desired amount of lead-in. The springfinger plate can further include a vertical wall and support a retainingleg that extends below the bottom of the corresponding port and caninclude a retaining member, where both help secure the thermal system tothe corresponding cage assembly. It should be noted, however, that thevertical wall, the retaining leg and retaining member are optional andone or the other may be used (or both omitted) depending on theapplication.

To secure the side walls to the main wall, grooves can be provided tohelp secure the side walls in place. In an embodiment, the side wallscan be soldered in place. As the spring finger plates are also expectedto be soldered in place (although such a construction is not required),certain economies of scale can be obtained if everything is solderedtogether at once.

As can be appreciated, one benefit of the discussed design variations isthat the thermal energy from the top of the inserted module can beremoved. As thermal energy rises, the top of the module tends to be thehottest and therefore the depicted design keeps the system relativelycompact and efficient at directing thermal energy from the module out ofthe system. One benefit of the design discussed herein is that they arecompact and thus helps increase the number of connectors that can bepositioned in a particular space. Of course, this additional compactnessdoes decrease the surface area of the option fins which limits itsability to dissipate heat. It is expected that for certain designs itmay be more desirable to have the fins on the main wall removed and toreplace the fins on the upper side wall with a liquid cooled chamber.The depicted connector system, therefore, is not limited to working withone particular thermal dissipation system.

The disclosure provided herein describes features in terms of preferredand exemplary embodiments thereof. Numerous other embodiments,modifications and variations within the scope and spirit of the claimsand the disclosure will occur to persons of ordinary skill in the art.

We claim:
 1. A connector, comprising: a cage that defines a first portand a second port, the cage configured to be supported by a circuitboard, the first and second ports being vertically stacked relative tothe supporting circuit board, and the first and second ports each havingfour walls; a plurality of spring finger plates, each spring fingerplate forming a wall of each of the first and second ports andsupporting a plurality of spring fingers, the plurality of springfingers configured to engage a module inserted into one of the first andsecond ports in a first direction, the spring fingers configured totranslate in a second direction, in operation, when the module isinserted into one of the first and second ports, wherein each springfinger of the plurality of spring fingers is configured to individuallycontact the module inserted into one of the first and second ports; andat least one heat transfer plate in thermal communication with a springfinger plate of the plurality of spring finger plates.
 2. The connectorof claim 1, wherein the spring finger plate in thermal communicationwith the at least one heat transfer plate is soldered to the at leastone heat transfer plate.
 3. The connector of claim 1, wherein the springfinger plate in thermal communication with the at least one heattransfer plate is attached to the at least one heat transfer plate witha thermally conductive adhesive.
 4. The connector of claim 1, whereineach of the spring finger plates forming a wall of the first port are inthermal communication with spring finger plates forming adjacent wallsof the first port.
 5. The connector of claim 1, wherein the plurality ofspring finger plates comprise four spring finger plates forming the fourwalls of the first port and four spring finger plates forming the fourwalls of the second port.